NUMBER CCLIV.-SEPTEMBER. ... Page Prof. E. Edlund on the Construction of the Galvanometer used in Electrical Discharges, and on the Path of the Extra Currents through the Electric Spark 169 Prof. J. LeConte on some Phenomena of Binocular Vision.... 179 Mr. C. Tomlinson on the Formation of Bubbles of Gas and of Vapour in Liquids... 204 Dr. T. Fritzsche on the Production of a Columnar Structure in Metallic Tin .... 207 Prof. W. A. Norton on the Fundamental Principles of Mole- 208 215 Mr. C. Tomlinson on the Supposed Action of Light on Combustion 217 Mr. J. Croll on the Opinion that the Southern Hemisphere loses by Radiation more Heat than the Northern, and the supposed Influence that this has on Climate Prof. G. C. Foster on some Lecture-experiments in Electricity. 229 Proceedings of the Geological Society : 220 Prof. W. King and Dr. T. H. Rowney on the so-called Prof. T. H. Huxley on Hyperodapedon 238 Mr. W. Whitaker on the Locality of a new Specimen of 240 Mr.W. H. Baily on Graptolites and allied Fossils occurring 241 ... 242 Africa.. ..... Dr. Sutherland on Auriferous rocks in South-eastern Note on Electrolytic Polarization, by Professor Tait 243 On the Spectrum of the Aurora Borealis, by J. A. Ångström.. 246 On the Thermal Energy of Molecular Vortices, by W. J. Macquorn Rankine, C.E., LL.D., F.R.SS. Lond. & Edinb. &c... 247 242 NUMBER CCLV.-OCTOBER. Dr. W. M. Watts on the Spectra of Carbon. (With a Plate.) 249 263 on the Hypothesis of Undulations with Ditscheiner's determi- nations of Wave-lengths and corresponding refractive Indices 268 Prof. E. C. Pickering's Observations of the Corona during the Dr. H. Herwig's Investigations on the Conformity of Vapours The Earl of Rosse on the Radiation of Heat from the Moon. 314. Proceedings of the Geological Society :- Mr. E. Hull on the Evidence of a ridge of Lower Carboni- On the Employment of the Spectroscope in order to distinguish a feeble Light in a stronger one, by M. J. M. Seguin .... 325 On the Mean Velocity of the Motion of Translation of the Mo- Dr. Marcet's Observations on the Temperature of the Human Lieut. J. Herschel on that portion of the Report of the Astro- nomer to the Madras Government on the Eclipse of August 1868 which recounts his Spectroscopic Observations. ... MM. C. Börgen and R. Copeland's Short Account of the Win- terings in the Arctic Regions during the last fifty years.... 340 M. F. Zöllner on a New Spectroscope, together with contribu- Page Mr. J. W. Judd on the Origin of the Northampton Sand. 400 40. Mr. W. Carruthers on the Structure and Affinities of Si- 402 Dr. H. A. Nicholson on the British Species of the Genera 402 On the Emission and Absorption of Heat radiated at Low Temperatures, by G. Magnus Mr. F. O. Adams on the Coal-mines at Kaianoma 402 403 403 On the limits of the Magnetization of Iron and Steel, by Prof. 404 On the Reflection of Heat from the surface of Fluor-spar and other Bodies, by G. Magnus 405 On the Luminous Effects produced by Electrostatic Induction in 407 NUMBER CCLVII.-DECEMBER. Mr. C. Tomlinson on the Motions of Camphor on the Surface of 409 .... 424 428 Prof. A. Kenngott's Microscopical Investigation of thin polished 430 M.Abich on Fulgurites in the Andesite of the Lesser Ararat, and on the Influence of Local Agents on the Production of Thunderstorms 436 M. Abich on Hailstorms in Russian Georgia. (With a Plate.) 440 Mr. T. T. P. B. Warren on Electrification .. 441 Prof. J. Plateau's Experimental and Theoretical Researches into the Figures of Equilibrium of a Liquid Mass without Weight.-Eighth Series 445 Dr. W. Odling on a Theory of Condensed Ammonia Compounds. 455 M. J. G. Fitch's Methods of teaching Arithmetic.-Dr. J. Proceedings of the Royal Society: Mr. T. Graham on Hydrogenium.. 457 459 Proceedings of the Geological Society : Page 465 466 M. F. Ruschhaupe on the Salt-mines of St. Domingo ... 466 467 On the Extension of Liquids upon each other, by R. Ludtge.. 468 On the Measurement of the Electrical Conductivity of Liquids hitherto supposed to be Insulators, by Thomas T. P. Bruce Warren 470 471 On the Freezing-point of Water containing dissolved Gases, and on the Regelation of Water, by C. Schultz .... Disturbances of Respiration, Circulation, and of the Production of Heat at great heights on Mont Blanc, by M. Lortet .... 472 Index .... 476 PLATES. I. Illustrative of Dr. H. M. Watts's Paper on the Spectra of Carbon. III. Illustrative of Prof. A. Kenngott's Microscopical Investigation of thin polished Laminæ of the Knyahynia Meteorite, and M. Abich's Paper on Hailstorms in Russian Georgia. THE LONDON, EDINBURGH, AND DUBLIN PHILOSOPHICAL MAGAZINE AND JOURNAL OF [FOURTH SERIES.] JULY 1869. I. On some Electromagnetic Phenomena considered in connexion with the Dynamical Theory. By The Hon. J. W. STRUTT, Fellow of Trinity College, Cambridge*. IT is now some time since general equations applicable to the conditions of most electrical problems have been given, and attempts, more or less complete, have been made to establish an analogy between electrical phenomena and those of ordinary mechanics. In particular, Maxwell has given a general dynamical theory of the electromagnetic field†, according to which he shows the mutual interdependence of the various branches of the science, and lays down equations sufficient for the theoretical solution of any electrical problem. He has also in scattered papers illustrated the solution of special problems by reference to those which correspond with them (at least in their mathematical conditions) in ordinary mechanics. There can be no doubt, I think, of the value of such illustrations, both as helping the mind to a more vivid conception of what takes place, and to a rough quantitative result which is often of more value in a physical point of view, than the most elaborate mathematical analysis. It is because the dynamical theory seems to be far less generally understood than its importance requires that I have thought that some more examples of electrical problems illustrated by a comparison with their mechanical analogues might not be superfluous. As a simple case, let us consider an experiment first made by De la Rive, in which a battery (such as a single Daniell cell) *Communicated by the Author. † Philosophical Transactions for 1865. Phil. Mag. S. 4. Vol. 38. No. 252. July 1869. B |
